Dioxazine-type dyestuffs and process for preparing the same



Patenied Dec. 14, i943 YATES PATENT OFFICE DlGXAZINE-TYPE DYESTUFFS AND PROC- ESS FOR PREPARING THE SAME No Drawing. Application January 21, 1943, Serial No. 473,118

8 Claims.

This invention relates to novel dyestufi compounds suitable for dyeing cotton and other textiles, and to a process of preparing the same, this application being a continuation-in-part of my copending application Serial No. 393,484, filed May 14, 1941.

More particularly, this invention deals with novel dioxazine-type dyestuiis which are obtainable by causing oleum, sulfuric acid or chlorosulfonic acid to act upon a compound of the general formula SOaH wherein each of the benzene radicals marked A has at least one free ortho-position, and wherein Z and Z individually represent hydrogen, halogen or alkyl, while B i the radical of an azole compound selected from the group consisting of the benzpyrazoles and the benztriazoles. EX- pressed in different words, R is the radical of a compound of the general formula wherein Y stands for OH or N, X stands for hydrogen, alkyl, hydroxy-alkyl, and aryl, including in the latter term substituted aryl such as dihalogen-aryl, etc.; while the hydrogen atoms of the B2 ring may be replaced by customary auxochromic substituents, such as alkyl, alkoxy or halogen.

The treatment of the above type compound with oleum, etc., results in closure of the two rings next to the central quinone radical, yielding a dioxazine dyestuff. This effect, however, is accompanied by sulfonation, and in the subsequent treatment of the product, some desulionation or shifting Of the SOsI-I groups takes place, as a result of which the formula of the final product is uncertain. The most that can be said about the final product is that it probably corresponds to the general formula from compounds in the prior art having the same general formula, in the structure of R. In the novel compounds of this invention R is the radical of an azole, and i therefore characterized by a structure consisting of one homocyclic ring of 6 carbon atoms and of one heterocyclic 5- membered rin fused together.

I have found that dioxazine dyes as thus defined have outstanding qualities as dyestufis for W001, giving strong and brilliant dyeings of good light-fastness and excellent wash fastness. They also possess excellent afifinity for cotton fiber, and as a result of these two properties the novel dyes of this series are particularly suitable for dyeing union fabrics. In addition, they may also be used for dyeing silk, regenerated cellulose and nylon fibers.

-The synthesis of my novel compounds may follow in general the prior practice of the art except for the choice of R. In some cases, however, I may include in this process a special after-treatment step with anhydrous I-ICl (or NaCl-l-anhydrous H2504) at elevated temperature, as more fully illustrated in Example 1 below. I find that this step enhances the exhausting properties of the final dyestufi, and gives altogether greater tinctorial strength and Washing fastness.

Considering now my process in greater detail, the synthesis of my novel dyestufis may begin by reacting a nitro-halogen-benzene sulfonic acid, for instance i-nitro-l-chlorobenzene-Z-sulfonic acid, with a Bz-amino azole of the type HzN-R, wherein R. is the radical of an azole as above defined. The condensation is effected by the aid of an acid absorbing agent, and may be expressed by the following typical equation:

SIOsH SIOsH (III) Condensation product III is then subjected to reduction, for instance by the aid of iron and acid, to convert the nitro group into an amino group. Two moles of the reduction product are then condensed in the usual manner with one mole of a benzoquinone selected from the group consisting of benzoquinone, its homologs and halogen derivatives, this condensation again beingaided preferably by acid absorbing agents. The result is a compound of Formula I above.

Finally, the compound of Formula I above is subjected to ring closure by the aid of sulfuric acid, oleum or chlorosulfonic acid, which results in a dyestufi".

As a, special added feature of this invention, I prefer in certain cases to treat the recovered dyestufi? by warming it up in concentrated sulfuric acid (96 to 100% strength) containing a small quantity of sodium chloride, or into which dry HCl gas is fed in catalytic proportions. A small quantity of glacial acetic acid 1 to 2% by Weight) may also be added.

Without any intent to limit this invention, the following examples are given to illustrate my preferred mode of operation. Parts mentioned are by weight.

Example 1 6.2 parts of tetra-chloro-benzo-quinone (chloranil) are condensed with 16 parts of the compound:

which may be named 5-(4'-amino-2-sulfoani lino)-l-methyl-benztriazole, and is prepared as described below. This condensation is carried out by heating the two reagents together with 8.2 parts of sodium acetate (anhydrous) or 8.4 parts of sodium bicarbonate and 250 parts of alcohol at reflux for 16 hours, followed by filtering off the precipitate while hot and washing the cake with 50 parts of hot alcohol and drying. There is thus obtained 24 parts of a dark condensation product, which is nearly insoluble in alcohol. This product most probably corresponds to the formula Cl S 0311 /HN\ o /NHR 1v) RHN/ 0 NH wherein R, is the radical of N-methyl-benztriazole.

Five parts of this condensation product are now added slowly, at 23 to 25 C., to 100 parts of fuming sulfuric acid containing 20% sulfuric anhydride; the solution is kept for three hours at 23 to 25 C., whereupon the temperature is raised to C. and kept there for one hour. The reaction mixture is added to ice, and the precipitated dyestuif is filtered oil and Washed with sodium chloride solution until free of mineral acidity. The wet filter cake is slurried in water and neutralized with soda ash; the sodium salt of the dye is then salted out and filtered. After drying, the dye is obtained in good yield as a purple product. It dyes animal and vegetable fibers bright blue tints of good light fastne Instead of raising the temperature to 45 C. as in the example above, the reaction mixture may be diluted with suficient 78 to 93% sulfuric acid to obtain finally a monohydrate solution; or the ring-closed dye may first be isolated as described above, dried and then added to monohydrate. In the former case the addition of some sodium chloride is preferable. In both cases, the reaction mixture is kept at 100" C. for about one hour, drowned in ice and isolated in the above-described manner. Noticeably redder shades of blue are obtained by this treatment at the higher temperature.

Similar redder shades of blue are obtained by substituting 30% oleum for the 20% oleum in the above example. By substituting 2% oleum instead, somewhat greener shades are obtained. The yields are in all cases about the same.

A similar dye is obtained by using chlorosulfo-nic acid instead of the oleum in the above example. This dye may be redissolved in monohydrate at temperatures from to C., as in the above example, and isolated in the same manner, resulting in a similar change of shade.

Example 2 5 parts of the dark condensation product as obtained in the first step in Example 1 are added to 100 parts of sulfuric acid monohydrate and the reaction mixture is heated to 0., kept there for one-half hour, and then isolated as a sodium salt as in Example 1. The dye is obtained in good yield as a dark powder. It dyes animal and vegetable fibers bluish-gray tints of good light fastness.

Example 3 Example 1 is repeated, except the tetra-chlorobenzoquinone is replaced by the molecular equivalent of toluquinone. The dye is obtained in good yield as a dark purple powder. It dyes animal and vegetable fibers in bluish-gray tints of good light fastness.

Example 4 Example 1 is repeated, except the tetra-chlorobenzoquinone is replaced by the molecular equivalent of benzo-quinone.

The dye is obtained in good yield as a dark powder. It dyes animal and vegetable fibers in bluish-gray tints of good light fastness.

Example 5 Example 1 is repeated, except that the tetrachloro-benzo-quinone is replaced by a molecular equivalent of 2:5-dichloro-benzo-quinone.

The dye is obtained in good yield as a dark powder. It dyes animal and vegetable fiber in bright blue tints of good light fastness.

Example 6 Example 1 is repeated except that the tetrachloro-benzo-quinone is replaced by the molecular equivalent of tetra-bromo-benzoquinone. The dye is obtained in good yield as a dark powder. It dyes animal and vegetable fiber in blue tints of good light fastness.

The initial anilino-b-enztriazole compound employed in the examples above may be prepared according to my copending application Serial No. 393,483, by condensing i-nitro-z-sulfo-lchloro-benzene with 5-amino-l-methyl-benztriazole, which in turn may be prepared from E-nitro-Z-methylamino-aniline by diazotization and subsequent reduction of the nitro group. The mentioned condensation may be effected by heating under pressure an aqueous solution of the two intermediates in the presence of magnesium oxide, and is followed by reduction of the nitro group in the intermediate diarylamine to the corresponding amine.

In a manner similar to the above examples, numerous other dyes of the dioxazine series may be prepared, by replacing the initial intermediate there employed by any other intermediate of the general formula may be selected and of the shades obtained thereby. In all the cases of this table, l-nitroby ring-closing a quinone diamine of the general formula l-chlorobenzene-2-sulfonic acid was employed Z sosn as initial material for condensation with the /\/NH\ amino-benztriazole or pyrazole, while chloranil 5 was selected to furnish the central component of I the dioxazine system. The shades indicated are 0% NH those obtainable on cotton or wool by the reo s sulting dyestufi.

Ex. Azole component Formula 2:3 a

7".-- 5-amino-bcnztriazole NH2- 1T'H Reddish-blue.

S 5-amino-l-ethylbr=n fria ole NHFQT C2H5 u 9 5-amino-1-bctahydroxy-ethylbenztriazole NHg-QT-CzH-lOH Do.

10---- 5-amino-l-phenylbenzfriamle H QIIF 0 3 gr eni h-blue,

| 11-.-. 5-amino-1(2,5-dich1oropl1enyl)-benztriazole NHz-QT-Q Do.

l N=N 01 12...- 5-amino-benzpyrazole... HzN- 1TH Do.

HC=N

13 5-amino-l-methylbcnzpyrazole H;NQNOH3 Blue.

HC=IL In each case, the triazole component was prewherein each of the benzene radicals marked A pared from the corresponding S-nitro-phenylene has at least one free ortho position, and wherein diamine (substituted as specified in the l-amino Z and Z individually represent a substituent segroup), by diazotization and subsequent reduclected from the group consisting of hydrogen, tion of the nitro group. The benzpyrazole comhalogen and alkyl, while R is the radical of an ponents of Examples 12 and 13 were prepared by azole compound selected from the group consist.- duction of t e p d g 5-nitro coming of benzpyrazoles and benztriazoles. pounds, according to Berichte, vol. 37, pages 2577 2. Dioxazine dyestuffs of the group obtainable and 2584. by causing a ring-closing agent selected from the If 2,5-dichloro-benzo-quinone is used instead group consisting of sulfuric acid, oleum and of chloranil in the dyestufi synthesis of Examples chlorosulfonic acid to react upon a quinone di- 7 to 13, similar shades are obtained, while benamine of th general formula zoquinone and toluquinone produce bluish grays Z SOBH in all cases.

It will be clear that the above examples are /NH R merely illustrative of the many combinations obtainable from the above-described products. For instance, instead of using chloro-benzo-quinones RNH/ 0 NH or toluquinone, longer chain alkylated benzo- 303E quinones may be used. 0

According to the present invention, a large Wherem Z represent substltuents from v m the group consisting of hydrogen, halogen and number of new dionazme colors of desil able shade n alkyl, while R is the radical of a benztriazole. and unusual light fastness are produced. These new dyes bosides Showing a good cotton affinity 3. Dioxazme dyestufis of the group obtainable by causing a ring-clogging agent selected from the and light fastness, are also of part1cular value as group consisting of sulfuric acid, oleum and chlo- Wool dyes for mlxed fibers smce they dye the rosulfonic acid to react u on a uinone diamine fiber uniformly and show a surprising brightness of the eneral formula p q on wool. The good wool-dyeing properties of my g 01 so H new series of dyes, particularly those containing v I 3 alkyl groups, appear to be caused by the presence /HN\ o /NHR of a special heterocyclic ring, which in certain cases adds, to a small degree and through its own double bond, to the color of the resulting dye.

I claim: g H 01 1. Dioxazine dyestufis of the group obtainable a wherein R is the radical of a triazole having the formula wherein X stands for hydrogen, allzyl, hydroxyalkyl or aryl.

4. A dioxazine dyestuff as defined in claim 3, B being the radical of l-methyl-benztriazole attached to the NH group in the 5-position.

5. A dioxazine dyestutf as defined in claim 3, R being the radical of 1-beta-hydroXyethy1-benztriazole attached to the NH group in the 5-position.

6. A dioxazine dyestufi as defined in claim 3, B being the radical of 1-dichlorophenyl-benztriazole attached to the NH group in the 5-position.

7. In the process of producing a dioxazine dyestuff, the steps comprising first reacting a benzequinone with substantially two molal proportions of an amino-diaryl-amine sulfonic acid of the formula NHR SOaH

wherein at least one of the positions ortho to the NHz group is free, and wherein R is the radical of an azole compound selected from the group consisting of benzpyrazoles and benztriazoles, and.

then reacting upon the intermediate quinone-diamine thus formed with an agent adapted to close the rings adjacent to the quinone nucleus.

8. The process of producing a dioxazine dyestuff which comprises reacting tetrachloro-quinone with substantially two molal ratios of an aminodiaryl-amine-sulfonic acid of the formula wherein R is the radical of a benztriazole, and then reacting upon the intermediate quinone-diamine thus formed with an agent of the group consisting of sulfuric acid, oleum and cholorsulfonic acid, whereby to close the rings adjacent to the quinone nucleus.

FRITHJOF ZVTILGMEYER.

CERTIFICATE OF CORRECTION.

Patent No. 2,556,521. December 1h, 19u5.

FRITHJOF zwILGMEYER.

It ie hereby certified that error appears-in the printed specification ofthe above npmbered patent requiring correctiorzas follows: Page 5, second column, line 65, claim 5, for "ring-clogging" read -ringclosing-; page h, second column, line 21-22, claim 8, for "cholorsulfonic" read 7 chlorosulfonic; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. 1

Signed and sealed this 29th day of February, A. D.-19hh.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

